SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '37e86eac5314a32e0174f0fbd46370c8b44120bc2bae5584f36c784f8a8bf887' 
  AND token = 'DC+KU2uqijRgDNP9Lfy+CIKOgMya0owYZDnOvR4BgVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}